NRC Statement on 10-Mile-Radius Emergency Planning Zones for U.S. Nuclear Power Plants

The NRC sees no basis at this point for expanding the 10-mile-radius Emergency Planning Zone (EPZ) around U.S. nuclear power plants. The current EPZ size has been in use since the 1970s and was the result of extensive emergency planning studies performed by a federal task force. That task force concluded a 10-mile-radius EPZ would assure that “prompt and effective actions can be taken to protect the public in the event of an accident” at a plant. This was based on research showing the most significant impacts of an accident would be expected in the immediate vicinity of a plant and therefore any initial protective actions, such as evacuations or sheltering in place, should be focused there.

Put another way, the projected radiation levels would not be expected to exceed EPA protective action dose guidelines (1 rem to the body or 5 rem to the thyroid) beyond 10 miles under most accident scenarios.

That does not mean the protective actions could not expand beyond the 10-mile radius. Rather, emergency planners have always known such actions could be necessary if the situation warranted it. Indeed, U.S. nuclear power plants are required to consider and drill for the possibility of radiation releases that could have impacts up to 50 miles away.

The advisory to Americans living within 50 miles of the Fukushima Daiichi plant in Japan was based on calculations done by NRC experts indicating releases from the three hobbled Japanese reactors and two fuel pools could – and a key word here is could – possibly exceed conservatively set safe radiation-exposure limits for the public. This advisory was made using limited data and conservative assumptions. As the NRC carefully monitored developments there, the agency used the best information available to it to make a protective action recommendation.

Neil Sheehan

NRC Public Affairs Officer

Region I